Towing Mystery

[larryo]

I've been researching 2016 Yukon XL's because of the current 0% financing offer.
1. It appears most Yukons come with a 3.08 rear end.
2. According to GMC's towing data, a Yukon XL (4WD) with a 3.08 rear end can tow up to 6000 lbs, while a Yukon XL (4WD) with a 3.42 rear end can tow up to 8000 lbs.

Assuming everything else (engine, transmission, chassis) is the same, why does changing the gear ratio in the rear end vary what the vehicle can tow by 2000 lbs?

 

[Yukon John]

The 3.42 gives better mechanical advantage...especially in a towing situation.

 

[larryo]

The 3.42 gives better mechanical advantage...especially in a towing situation.

I can understand how lower gearing would be helpful starting up from a stop or merging onto a freeway, but that doesn't explain why one vehicle can tow 2000 lbs more than the other.

 

[Kpwweb]

I think the 3.42s only come with the towing package. Therefore, all else is not equal. Bigger brakes, tranny and engine oil cooler, two-speed beefier transfer case if 4wd. I think my build sheet also stated something about a heavy-duty or reinforced frame...

So it's not just the gears--but they do help.

 

[Kpwweb]

Also rear load-leveling shocks.

 

[gat0r]

^ also integrated electric trailer brake controller

 

[Yukon John]

I can understand how lower gearing would be helpful starting up from a stop or merging onto a freeway, but that doesn't explain why one vehicle can tow 2000 lbs more than the other.

I think this may answer most of your questions. It's all about the total package.

http://www.trucktrend.com/how-to/towing/1502-sae-j2807-tow-tests-the-standard/

 

[larryo]

Thanks for all the input, it helps.
I can see that there is more involved than just rear end gearing.
I have searched on the internet, without success, for a definition of the GMC Yukon Max Towing Package.
The dealer's website only lists a Heavy duty trailering package as an included option.

 

[1BADI5]

Both my 08 Tahoe LTZ 4x4 and my 99 Yukon SLE 4x4 have the factory tow packages both have the same add ons;

1. 3.73 gears (RPO code GT4)
2. Locking diff (RPO code G80)
3. Transmission coolers
4. Oil cooler
5. Heavy duty suspension (RPO codes either Z85 or Z82)

Having the lower gears either 3.42 or 3.73 get better use of low end torque....which you kind of need to move heavy load from a stop to your desired speed. The 3.08s are straight highway gears for a full size SUV where GM is trying to play with the EPA mileage game

 

[1BADI5]

Thanks for all the input, it helps.
I can see that there is more involved than just rear end gearing.
I have searched on the internet, without success, for a definition of the GMC Yukon Max Towing Package.
The dealer's website only lists a Heavy duty trailering package as an included option.

Go to a dealer and compare the RPO codes with a tow package equipped truck and the RPO codes from a non-tow package equipped truck. All I do is take my phone and snap pics of the RPO code listing in the glove box and then use one of the countless online RPO code decoders to see whats what.

The offered gearing ratio will be your indicator or the window sticker with the options.

 

[larryo]

Towing Mystery SOLVED
Earlier I said I couldn't find a website that showed RPO codes for the 2016 Yukon. Well instead of searching for GMC RPO codes in general, I did a search on a specific GMC Yukon RPO code (Z82 - Trailering Equipment Heavy duty) and came across this site:
http://media.gmc.com/media/us/en/gmc/vehicles/yukon_xl_denali_xl/2016.tab3.html

This site shows what RPO's are standard on a Yukon and which are options.
I printed these out and took them to the dealer.
I actually found ONE vehicle (2016 Yukon XL SLT) on their lot that had RPO NHT which is the HD Trailer package that includes (GU6) 3.42 gear ratio, (JL1) Trailer brake controller, (Z85) Suspension package with air leveler and (NQH) heavy duty transfer case. It also had the Z82 option I mentioned above.
So, since this vehicle had exactly what I was looking for, I bought it. And I was able to get 0% financing for 72 months.
I have a 26 ft travel trailer that I tow. It's GVWR is 6000 lbs although I usually run under that. My 2015 Yukon SLE was rated to tow 6000 lbs. With the XL SLT my tow weight limit is now 8000 lbs. I will feel much better towing with this one.
Thanks for everyone's comments and suggestions.

 

[1BADI5]

Awesome, glad I was of some assistance .....time to have a beer now

 

[Yukon John]

Towing Mystery SOLVED
Earlier I said I couldn't find a website that showed RPO codes for the 2016 Yukon. Well instead of searching for GMC RPO codes in general, I did a search on a specific GMC Yukon RPO code (Z82 - Trailering Equipment Heavy duty) and came across this site:
http://media.gmc.com/media/us/en/gmc/vehicles/yukon_xl_denali_xl/2016.tab3.html

This site shows what RPO's are standard on a Yukon and which are options.
I printed these out and took them to the dealer.
I actually found ONE vehicle (2016 Yukon XL SLT) on their lot that had RPO NHT which is the HD Trailer package that includes (GU6) 3.42 gear ratio, (JL1) Trailer brake controller, (Z85) Suspension package with air leveler and (NQH) heavy duty transfer case. It also had the Z82 option I mentioned above.
So, since this vehicle had exactly what I was looking for, I bought it. And I was able to get 0% financing for 72 months.
I have a 26 ft travel trailer that I tow. It's GVWR is 6000 lbs although I usually run under that. My 2015 Yukon SLE was rated to tow 6000 lbs. With the XL SLT my tow weight limit is now 8000 lbs. I will feel much better towing with this one.
Thanks for everyone's comments and suggestions.

Love the color..."Crimson Red Tintcoat"

Wonder why ??? LOL

The standard wheel base 2 wheel drives carry a 8500# tow rating. I tow a 26' Formula that with a full tank of gas plus trailer weighs 7500#. Glad I got the Max Tow...my new Yukon pulls the boat much easier than my LQ9 6.0 Vortec HD Escalade ESV did...and it had 3.73 gears.

I have 600# tongue weight and the Auto Ride rear suspension keeps the truck level at all times.

The only thing I don't like is the "Dinky" side view mirrors they give us. I plan to upgrade mine to Escalade Mirrors soon...they are about twice as big and are a direct bolt on.

Enjoy yours...you made a great choice.

 

[larryo]

Love the color..."Crimson Red Tintcoat"

View attachment 66458

Wonder why ??? LOL

The standard wheel base 2 wheel drives carry a 8500# tow rating. I tow a 26' Formula that with a full tank of gas plus trailer weighs 7500#. Glad I got the Max Tow...my new Yukon pulls the boat much easier than my LQ9 6.0 Vortec HD Escalade ESV did...and it had 3.73 gears.

I have 600# tongue weight and the Auto Ride rear suspension keeps the truck level at all times.

The only thing I don't like is the "Dinky" side view mirrors they give us. I plan to upgrade mine to Escalade Mirrors soon...they are about twice as big and are a direct bolt on.

Enjoy yours...you made a great choice.

I haven't towed with mine yet. I have to put at least 500 miles on it though by next weekend because we have a trip planned.
I agree, the small mirrors suck. I have add on mirrors from the Yukon I traded in.
The Escalade mirrors sound interesting but will they have all the functions my existing mirrors have (folding, tilting, blind spot etc)?

 

[Yukon John]

The Escalade mirrors sound interesting but will they have all the functions my existing mirrors have (folding, tilting, blind spot etc)?

Yes...plus they have bigger puddle lights and cameras. I have a local geek that has reprogramed a few Tahoes/Yukons to give you wide angle rear view from the side view mirror cameras on screen when you flip the turn signal lever to the left or right....as the Escalade Platinum does....said he could do it in 2 hours for $100. This will be great for lane changes and turns in tight places.

My problem is that I'm towing a rig that is about 32' long in total and with the stock mirrors I can't see past the front axle of my twin axle trailer. This creates a REAL problem backing down a boat ramp or making sharp right turns. I Miss the Escalade mirrors on my '05...but otherwise my Yukon does a better job towing my boat than it did.

 

[Fifty]

Let me know about that mirror set up if you get it.
I'd do it for certain if I could get the cameras to work

 

[Kpwweb]

Those mirrors do sound interesting! Hmmmm.... I should study up on those.